Means for coupling from a single to a push-pull line



- Oct. 7, 1941. w. BUSCHBECK 2,258,107

MEANS FOR COUPLING- FROM A SINGLE TO A PUSH-PULL LINE Filed July is, 1939 INVENTOR WERNER BUSCHBECK ATTORNEY Patented Oct. 7, 1941 UNITED STATE MEANS For: COUPLING FROM A SINGLE. TO.

PUSH-PULL LINE Werner Buschbeck, Berlin, Germany,

assignor to Telefunken- Gesellschaft fiir Drahtlose Telegraphic in. b.- H.,

tion of Germany Application July 15,

In Germany Berlin, Germany, a corpora- 1939, Serial No. 284,645

August 9, 1938 Claims. (01. 178-44) Many instances are I an arrangement which presents symmetry ground must'be coupled to an arrangement which is dissymmetric to ground, or vice versa. A case like that arises for example, when'the output end of a push-pull scheme must be put coupling relation with a load resistance, oneend of which is earthedpor where a symmetrical ana dipole antenna, is to be connected feeder line, say, a 'concen- In all of these to branch off contenna, say, with a dissymmetric tric or co-axial energy line.- cases it is known in practice ductors which have potentials symmetric ground by way of connecting lines of corre- X sp'ondingly dissimilar electrical length, .trom a '15 1- 1 common potential point of the dissymmetric ar- 60=U X U rangement. But the identical result is securable j 'X) by a far simpler scheme, that is, quasi-stationmy moans. According to the invention, in an The internal impedance Zi of the equivalent orarrangement designed to couple a mm r ab gamzation 15 obtained most conveniently by derangement to a dissymmetric arrangement, a ter of impedance between the network of negligible internal resistance is protermmals; l the Source potentiali'U vided between the dissymmetri'c arrangement bemg short'clrculted- Thusand one-half of the symmetric arrangement 7 adapted to turn the potential an angle of 130 .de- Jib 172 arrangement is directly united with the di'ssym- .7 75- metric one. Preferably the connecting network consists of a T type mesh in which the impedance These ,flatlons are represfented F Flgure of the series arms is of inverse sign and twice the 111 order F make 1t P05511316 for the two absolute value of the impedance of the cross arm ground',sy mmetr lc potentlals U to Work, mgjrther or element upon a Jo nt resistance R, the upper potential U In what follows the operation of the invention In t as already Pomted Whlle P i shall be explained 'in greater detail by reference Servmg Its amphtude" mu 5t expenence Shlft to the drawing in which Figure Shows a in phase of 180 degrees in other words, there schematicrepresentati-on of the invention; Figmust be ures 2 and 3 show'filter meshes used in further EO= U iiifit iiiw filttlifiits? 3 211251321116; The W111 be readily the as can e satisfying requirements of theinvention; Figures 40 the formulas 1f 5 Instance 5a and Show modifications of Figures 4a and also the internal impedance, as follows also from 411 useful where a nominally symmetric source is Formula 2 eqllal t0 F With the result that not actually so and Figure 6 Shows a further also a combination of inverse sign of X results bodiment of the invention in the identical effect. In Figures 4a and 4b the Referring to Figure 1, this first shows a sche- 5 t p st rms f a phas v s n m sh matic representation of the invention. What is according t the nv nt n ar r pr s nt d, the

shown here are the two potentials U symmetric impedances ofthe series arms in Figure 4a being to ground, these potentials being intended to of negat ve n, While in h case O F r b operate upon a load resistance R, one end of they have a positive sign. Beyond these inwhich is at ground potential. To this end a netstances, of course, there are many other combimet with in practice where to of potential supply R. Now, examining elements F :iX and the cross arm the presence of an input t potential 6 work T is interposed between one of the sources U and the load resistance a T mesh 'of the form shown in Figure 2 which comprises two similar series where n for the time being any arbitrary number; and considering the said T mesh as a quadripole (four terminal network), there results in potential U an output nations of T or 1r type meshes designed to fulfill the same purpose and which therefore come within the scope and the spirit of the present invention,

If the two potentials U are not of like size from the outset, then as demonstrated by Equation 1, any other, greater or smaller value of U may be obtained by choosing for n a value other than 2. The remaining internal reactance of the circuit organization which flows from Formula 2 can at any time be cut down to zero level by choosing a suitable dimension for the last series arm of the T mesh. Inasmuch as n must always be greater than unity for the purpose of phase reversal, this series element is able to change only its size, but never its sign. Thus, for instance, it can not change from a capacity into an inductance. What is, moreover, necessary as a general rule is to derive from the feeding potential only active (watt) current. Investigation of the direct graphic representation Figure 4a and Figure 4b shows that this problem is fulfillable by a reactance of the same size as the cross arm connected directly in parallel relationto the potential U. Presupposing equal potentials U, symmetric to ground, there results a circuit arrangement for the network T to be incorporated in Figure 1. of the kind represented in Figures 5a and 5b.

The invention has been described in connecuion with a dissymmetric consumer or load which is fed from a symmetric source of potential supply, though it will be understood that, as already pointed out above, the connections between load and potential source may be exchanged or reversed with the result that, for instance, also the connection between a symmetric transmitting aerial and a dissymmetric feeder lead is made feasible by using the basic idea of the invention.

Arrangements of the kind hereinbefore described may be used to advantage also if, for some practical reason, say, with a view to a reduction of energy of power, temporarily only one potential U, that is, for instance, only one-half the number of tubes is worked with. An arrangement of this kind is illustrated in Figure 6. Here the two tubes R1 and R2 work upon the common and joint load resistance R, the potential of tube R1, according to the invention, being turned an angle of 180 degrees by providing the network. In this circuit scheme it is readily feasible to cut off one of the two tubes R1 or R2. It is of advantage to disconnect the tube R2, for in this case the load is supplied capacitively from the inductive branch, and this curtails the harmonics to an appreciable degree. Because of the presence of the reactance +iX between the plate and the upper voltage divider, the plate load of tube R1 will always be purely ohmic in nature, regardless of the size of the load R.

I claim:

1. Circuit organization adapted to establish coupling relations between a radio frequency arrangement which is symmetric to ground and a dissymmetric arrangement, with the characteristic feature that between the dissymmetric arrangement and one-half of the symmetric arrangement there is interposed a network causative of a phase shift of 180 degrees and inherently possessing a vanishingly low internal resistance, while the other half of the symmetric arrangement is directly connected with the dissymmetric arrangement, said network consisting of a T type mesh having a pair of series reactances and a shunt reactance, the impedance of each of the series arms thereof compared to the impedance of the shunt reactance being twice the absolute value and of opposite sign.

2. A circuit organization as claimed in claim 1, with the characteristic feature that in said T type mesh the impedance of each of the series reactances compared to that of the shunt reactance is twice the absolute value thereof and of opposite sign and a second shunt reactance is connected across the first named one half of the symmetric arrangement.

3. A circuit organization adapted to establish coupling relations between a radio frequency organization having a pair of terminals adapted to be symmetrically energized with respect to a third terminal of fixed potential and a radio frequency organization having one terminal adapted to be energized with respect to another terminal of fixed potential comprising a direct connection from one of said pair of terminals to said one terminal, a pair of series connected reactances between the other of said pair of terminals and said one terminal and a third reactance connected from the junction of said pair of reactances to said terminals of fixed potential, the value of each of said series reactances being numerically equal to twice that of the third reactance and of opposite sign.

4. A circuit organization adapted to establish coupling relations between a radio frequency organization having a pair of terminals adapted to be symmetrically energized with respect to a third terminal of fixed potential and a radio frequency organization having one terminal adapted to be energized with respect to another terminal of fixed potential comprising a direct connection from one of said pair of terminals to said one terminal, a pair of series connected reactances between the other of said pair of terminals and said one terminal, a third reactance connected from the junction of said pair of reactances to said terminals of fixed potential, the value of each of said series reactances being numerically equal to twice that of the third reactance and of opposite sign and a fourth reactance connected from the other of said pair of terminals to said third terminal, said fourth reactance having a value equal to that of said third reactance.

5. A circuit organization adapted to establish coupling relations between a radio frequency source having a. pair of terminals symmetrically energized with respect to a third terminal of fixed potential and a radio frequency load having one terminal adapted to be energized with respect to another terminal of fixed potential comprising a direct connection from one of said pair of terminals to said one terminal, a pair of series connected reactances between the other of said pair of terminals and said one terminal, a third reactance connected from the junction of said pair of reactances to said terminals of fixed potential, the value of each of said series of reactances being numerically equal to twice that of the third reactance and of opposite sign and a fourth reactance connected from the other of said pair of terminals to said third terminal, said fourth reactance having a value equal to that of said third reactance whereby the resultant impedance across the other of said pair of terminals and said third terminal is purely ohmic, regardless of the impedance of said radio frequency load.

WERNER BUSCHBECK. V 

